Windows Doesn’t Assign Drive Letter to External and USB Flash Drives

Faced with such a problem: when I connect any external removable USB HDD or flash drive, Windows doesn’t assign a drive letter to it. When a drive is connected, a message appears indicating that a new device is installed, the drive appears in the Device Manager, but is not displayed in the File Explorer.

To make the drive available in the system, you must assign a drive letter through the Disk Management console each time manually. To do this, open the Computer Management console (via the Win + X menu) and go to the Storage section -> Disk management. In the list of drives, locate the connected removable USB drive. As you can see, the disk is online, it has one healthy partition with the NTFS, but it is not assigned with a drive letter. To assign a drive letter to it, right-click on the partition and select “Change Drive Letter and Path“.

In the window that appears, click the “Add” button, select “Assign the following drive letter” and select the letter you want to assign to the drive (for example, H: ) in the drop-down list and click OK.

After that, the connected USB drive appears in the File Explorer with the assigned drive letter. However, after disconnecting the USB device or restarting the computer, the drive letter won’t be assigned automatically to it. I have to assign the letter again manually through Disk Management, and that becomes annoying.

Tip. Make sure that Windows recognizes the partition (s) on the connected USB drive and the partition is formatted with the NTFS, FAT32 or exFAT file system. If the file system is detected as RAW, or the disk is unallocated, most likely the USB flash drive is just a new one or the partition table is damaged and you have to repair the file system at first.

It seems that some feature of automatic detection of partitions on the external hard disks fails. How to solve this problem?

First of all, make sure that the Virtual Disk service is running. You can check the status of this service in the services management console (services.msc).

If the service is stopped, start it from the graphical snap-in (Start button) or using the command:

net start vds

net start vds

Check if the problem persists. If it does, make sure that the automatic mounting of new volumes is enabled.

Note. When the automount is enabled, Windows automatically mounts file systems of new disks connected to the system and assigns drive letters to the partitions. If the automount is disabled, Windows detects new disks, but doesn’t automatically mount them or assign any letters to the new volumes.

Open the command prompt as administrator and run the following commands:

diskpart

diskpart

Within diskpart, make sure that the automatic mounting of new volumes is enabled:

DISKPART> automount

DISKPART> automount

Automatic mounting of new volumes disabled. As you can see, the auto-mounting is disabled. Let’s enable it:

DISKPART> automount enable

DISKPART> automount enable

Automatic mounting of new volumes enabled. Exit diskpart

DISKPART>exit

DISKPART> exit

Leaving DiskPart...

Note. By the way, the automount is also responsible for the fact that the system remembers the drive letters assigned to the removable drives at the previous connection (if these letters are not busy). To clear the saved associations, use the command DISKPART>automount scrub

Restart your computer and verify if the letters are assigned to the external USB drives.

If not, check if the “hidden” and “do not assign a drive letter” attributes are set for the partition on the USB drive. Run the Diskpart command line and enter the following commands:

After that, this partition on the USB flash drive should automatically be assigned a drive letter on any computer.

Also keep in mind that if there are several partitions on the USB flash drive, then Windows will only see the first partition. The ability to create multiple partitions on removable USB drives appeared only in Windows 10 1703. Previously, in order to make second and subsequent partitions on the USB flash drive were accessible in Windows, you had to use a trick to make Windows recognize USB flash drive as a HDD). If your USB flash drive doesn’t appear in the Disk Management console, try using a different USB port, cable. Try to connect the USB flash drive directly to the computer (without the USB hub), check whether the power is on, and whether it is recognized on other computers.

10 comments

dougApril 29, 2015 - 4:05 pm

Thanks, this worked great!

Reply

AltonAugust 1, 2015 - 6:50 pm

Finnally something that worked. 4 of my 9 USB keys no longer mount on my computer but worked on my wife’s so I knew it was a Windows problem. Gave up a year ago trying to solve the problem because none of the solutions on the web worked – and there are tons of them. So after loading Win 10 thought I would see if my keys worked they still didn’t so I did a google and this solution pooped up.

Reply

AsgharJanuary 31, 2016 - 4:58 am

This fix worked like charm. Thanks for posting friend.

Reply

JanMay 9, 2016 - 2:50 pm

Great help! Thank a lot!

Reply

ArkMay 31, 2016 - 8:54 am

Very helpful! Thank you very much!

Reply

Coral Bay CCJune 9, 2016 - 4:23 pm

You rock!!!! Been fighting this on a SBS 2011 server. Enabling automount did the trick. Thanks SO much!!

Reply

HutchDecember 3, 2016 - 7:02 pm

Well done – automount worked like a dream in Windows10 Anniversary edition (on my laptop). Many thanks.

Reply

SompopMarch 18, 2017 - 5:53 am

Good Job. Thank you verry much.

Reply

Virender SainiApril 2, 2017 - 5:48 am

Virtual Disk service is running aoutomount is anabled already disk drive is showing in device manger but drives still not shown in my computer